BIOL 1001 Chapter 3: Midterm 2 - Chapter 3, 20, 40
Document Summary
Occurs when some force or phenomenon affects the survival of individual organisms. Occurs when a large population of individuals is exposed to a lethal factor and only resistant individuals survive and reproduce. Key factors behind selection are a selective force (pressure) and the capacity for explosive population grown. Selection is the major force responsible for evolution and biodiversity. Sexual dimorphism: one gender is larger or more colourful than the other can be an outcome of sexual selection. Because a males large size, bright feathers or large horns indicate that he is particularly healthy. He can harvest resources efficiently or simply that he has managed to survive to an advanced age. The features are signals of male quality and if they reflect a males genetic makeup he is likely to fertilize a females eggs with sperm containing successful alleles.
